Disposal of human remains

ABSTRACT

An alkaline hydrolysis unit, and method of using the same to dispose of a cadaver, the alkaline hydrolysis unit comprising: a chamber for receiving a cadaver to be chemically decomposed, the chamber including a head-receiving part intended to receive the head of a cadaver; a recirculation pump fluidly connected to the chamber of the alkaline hydrolysis unit and adapted to recirculate fluids within the chamber; a head retaining means locatable in the chamber for retaining the head of the cadaver in the head-receiving part of the chamber; and at least one recirculation jet fluidly connected to the recirculation pump and positioned to aim fluid from the recirculation pump at the head-receiving part of the chamber.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority to, and is aDivisional application of, U.S. patent application Ser. No. 12/680,696,filed Mar. 29, 2010, which in turn is a 35 U.S.C. §371 national stagefiling of International Patent Application No. PCT/GB08/050897, filedOct. 3, 2008, and through which priority is claimed to Great BritainPatent Application No. 0719482.2, filed Oct. 5, 2007, the disclosures ofwhich applications are incorporated herein by reference in theirentireties.

The present invention relates to the disposal of human remains. Inparticular, the invention relates to disposal by alkaline hydrolysis. Acoffin for use in an alkaline hydrolysis process, an alkaline hydrolysisunit and a method and system for disposing of a cadaver are alsodescribed.

The disposal of human remains after death is currently done by eitherburial or cremation. Due to a lack of suitable and accessible land andthe high costs involved, cremation is becoming preferable to burial.However, cremation causes harmful emissions in the form of dioxins andmercury. Mercury is a big problem and in Europe, there is legislationpending to force crematoria to filter abate their emissions. This isexpensive and also requires very bulky equipment that takes up a lot ofroom.

A further problem with cremation is that it uses a lot of gas, andproduces large amounts of carbon dioxide, a greenhouse gas, whichcontributes to global warming. A further disadvantage of cremation isthe organic building blocks that make up the body and come from theecosystem are lost forever during the burning process.

Some problems with known alkaline hydrolysis methods used for disposalof regulated waste in hospitals, are that the alkaline hydrolysis unitneeds to be heated up for each load of waste, and then cooled down, sothat the waste fluids produced are cool enough to be received by thelocal sewer system. This uses a lot of energy, and causes long timeintervals between the disposal of successive waste loads. The energyused in heating and cooling is typically wasted, which contributes toglobal warming.

When disposing of regulated waste in hospitals, it is known torecirculate fluids within a decomposition unit by means of arecirculation pump. The hotter the operating temperature of thedecomposition unit, the faster and more efficiently the decompositionunit can operate. However, in the known processes, the maximum operatingtemperature of the decomposition unit is limited by the maximumoperating temperature that the recirculation pump can tolerate. This istypically only up to 155 degrees Celsius.

According to a first aspect of the invention there is provided a coffinfor use in an alkaline hydrolysis process, the coffin comprising adissolvable receptacle for a cadaver, the dissolvable receptacle beingdissolvable in the alkaline hydrolysis process.

By “coffin”, we mean any receptacle adapted to receive a cadaver. Theterm “coffin” is not limited to boxes, but can also encompass othercadaver receptacles, such as bags and rigid/flexible containers ofnon-cuboid shapes, as will be explained.

Substantially all of the dissolvable receptacle is decomposable in thealkaline hydrolysis process, together with the cadaver. Optionally, thecoffin is fully dissolvable in the alkaline hydrolysis process.

Optionally, the coffin is provided with an outer casing.

The outer casing typically resembles a conventional, wooden coffin, forpresentation to the public, and is removed prior to the alkalinehydrolysis process. Typically, the outer casing comprises one or morewooden panels sized to at least partially surround the coffin. Thepanels may be securable to the coffin or to a support frame used withthe coffin.

Typically, the dissolvable receptacle comprises one or more of silk,wool, or a bioplastic material.

Optionally, the entire dissolvable receptacle is bioplastic.

Bioplastics are made from organic sources, such as plant starch andsugar cane, instead of from petroleum. Once disposed of, manybioplastics will safely and naturally biodegrade. Most or all bioplasticmaterials are fully dissolvable by alkaline hydrolysis.

Advantages of bioplastic materials include that they may be strong,waterproof, light, simple to manufacture, and inexpensive. Waterproofembodiments do not require an additional waterproof liner. Additionally,the fact that bioplastic materials dissolve with the body makes themenvironmentally-friendly, since they will not end up in landfill sites,and they do not require any additional expenditure of energy to destroy.

Since at the end of the process, the coffin is dissolved together withthe cadaver, there is no need to clean and return any parts of thecoffin for future use. A bioplastic coffin also allows more rapidemptying and cleaning of the alkaline hydrolysis unit.

Optionally, the bioplastic coffin comprises a substantially rigidcontainer, which may or may not have a lid or cover. A suitablebioplastic material for forming such a container is known as “Mater-BiTF01U/095R” and is available from Novamont SpA, Via Fauser, 8 I-28100Novara, Italy.

The term “substantially rigid” is to be construed to mean solid in thesense of a box, in contrast to the more cloth-like flexibility of a bagor fabric.

Hence, “substantially rigid” encompasses box-like containers of anyshape, made from resilient materials.

Optionally, the container is injection-moulded. The coffin may be formedin any required shape. For example, the coffin could be formed as ahollow cuboid box, as is conventional. Alternatively, other shapes canbe used, for example more closely following the contours of a humanbody. Optionally, the shape of the coffin may be designed to co-operatewith the shape of the alkaline hydrolysis unit in which it will be used.The container may have any desired colour and optionally may be colouredto imitate wood, for aesthetic appeal.

Alternatively, the coffin may comprise a flexible bag, instead of asubstantially rigid container. If a bioplastic material is chosen, thebioplastic material could be a dissolvable starch based biopolymer, suchas a “Mater-Bi™ thermoplastic biodegradable polymer” that comprisesstarch, polyesters and plasticizers. This material is available fromNovamont SpA, Via Fauser, 8 I-28100, Novara, Italy. Such a bioplasticbag may be formed with very thin walls, whilst still being strong enoughto carry a cadaver and still being waterproof. Alternatively, bags ofsilk or wool or other dissolvable materials could be used.

Typically, the bag is an open bag, or a closeable bag which can beopened, to allow the cadaver to be viewed.

Optionally, the bag may be closeable (e.g. by a zip) such that thedissolvable receptacle fully surrounds and encloses the cadaver. The zipalso provides the tension required to form a “tent” type design thatfully hides that cadaver.

Optionally, the coffin also includes a waterproof liner that is adaptedto fit within or around the dissolvable receptacle.

The waterproof liner prevents body fluids from leaking out of thedissolvable receptacle.

The waterproof liner can comprise an open bag (to allow viewing of thecadaver), or a fully sealable, closed, bag. Embodiments comprising aclosed bag can be used for cadavers which have an infectious disease.

Typically, the waterproof liner comprises a dissolvable starch basedbiopolymer material, for example a “Mater-Bi™ thermoplasticbiodegradable polymer” comprising starch, polyesters and plasticizers.

The waterproof liner is typically sewn or otherwise attached to thedissolvable receptacle.

In alternative embodiments, the dissolvable receptacle is inherentlywaterproof (e.g. if the dissolvable receptacle is made from a bioplasticmaterial), and a separate waterproof liner is not required.

Optionally, the coffin also includes a non-dissolvable mesh receptacle,which will still be intact at the end of the procedure. The meshreceptacle typically comprises a plastic mesh. The mesh receptacletypically comprises a bag. The mesh does not impede the flow ofchemicals to the cadaver, which flow freely through the gaps in themesh.

Preferably, the mesh of the non-dissolvable mesh receptacle is fineenough to retain substantially all of the bone residue of the cadaver(e.g. bone fragments, any body implants) within the non-dissolvable meshreceptacle. This allows the alkaline hydrolysis unit to be emptied andcleaned more rapidly, because the non-dissolvable mesh receptacle cansimply be pulled out at the end, instead of having to pick up the boneresidue scattered throughout the chamber of the alkaline hydrolysisunit.

The non-dissolvable mesh receptacle can be used with any coffin of theinvention, whether silk or bioplastic, rigid or flexible.

The non-dissolvable mesh receptacle could be located inside or outsideof the dissolvable receptacle.

The non-dissolvable mesh receptacle may be separate to the dissolvablereceptacle.

Alternatively, the non-dissolvable mesh receptacle could be fixed to thedissolvable receptacle by any suitable means (e.g. lamination, bonding,adhesion, stitching, stapling).

Alternatively, the non-dissolvable mesh receptacle could be formedintegrally with the dissolvable receptacle.

In all embodiments, the dissolvable receptacle will be dissolved in thealkaline hydrolysis process, leaving the non-dissolvable mesh receptacleretaining the bone residue.

According to a second aspect of the invention there is provided a coffinassembly comprising:

-   -   a coffin as claimed in any preceding claim; and    -   a support frame for supporting the coffin.

The support frame can provide the required rigidity for any flexible bagembodiments, and allows the coffin to be handled easily. The metal ischosen so as to be not decomposable in the alkaline hydrolysis unit, sothe support frame can be re-used. Typically, the support frame is metal,for example, stainless steel.

Optionally, the coffin assembly also includes a head retaining means.

Preferably, the head retaining means is adapted to restrain verticalmovement of a head of a cadaver.

Optionally, the head retaining means is adapted to restrain movement ofa head of a cadaver in all directions.

Typically, the head retaining means comprises part of the support frame.

Alternatively, the head retaining means comprises a head strap.

Typically, the location of the head retaining means along thelongitudinal axis of the coffin is adjustable, to suit cadavers ofdifferent heights. Optionally, the support frame has elongate slots,which secure the head strap to the frame and along which the head strapcan be moved to adjust the longitudinal location of the head strap.

Preferably, the support frame comprises a stainless steel mesh.

Optionally, the support frame comprises a base and a plurality of poststhat are attachable to the base.

Preferably, the base includes low friction feet.

Preferably, the low friction feet comprise wheels, rollers, runners orbearings, which allow the frame to be easily rolled or slid on asurface.

Preferably, the posts are removable from the base (e.g. by screw threadattachments).

Optionally, each post includes attachment means adapted to attach tocorresponding attachment means provided on the dissolvable receptacle.Typically, the attachment means comprises at least one hook provided oneach post, and an equal number of loops, each provided at a respectivecorresponding location on the dissolvable receptacle. Alternatively, thehooks could be provided on the dissolvable receptacle, and the loops onthe posts. Further alternatively, entirely different attachment meanscould be provided, e.g. a hook and loop-type fastener (e.g. Velcro™ ) ora 3M™ Dual Lock™ fastening system.

Optionally, the base is generally rectangular and is provided with a rimon its two longitudinal sides. Optionally, the rim is also providedalong one end.

According to a third aspect of the invention, there is provided a methodof disposing of a cadaver, the method including the steps of:

-   -   placing the cadaver into a coffin comprising a dissolvable        receptacle;    -   placing the coffin in an alkaline hydrolysis unit; and    -   adding water and a chemical into the alkaline hydrolysis unit        with the cadaver, to break down the cadaver into a fluid        component and a bone residue component and to dissolve the        dissolvable receptacle of the coffin by alkaline hydrolysis.

Preferably, the chemical comprises potassium hydroxide. Alternatively,the chemical comprises sodium hydroxide.

Optionally, the coffin may include any of the features (optional orotherwise) of the first aspect of the invention.

Preferably, the method includes heating the inside of the alkalinehydrolysis unit, conserving at least some of the heat created, and usingthis heat to heat the alkaline hydrolysis unit when used for asubsequent cadaver.

Typically, the heat is conserved by transferring a heated fluid to aninsulated heat tank.

Optionally, the heated fluid comprises water that has been used to coolthe alkaline hydrolysis unit. Typically, this heated water is added intothe alkaline hydrolysis unit when used for the next cadaver.

Alternatively, the heated fluid comprises waste fluid from the alkalinehydrolysis process. Typically, this heated waste fluid is used to heatmains water in the insulated tank, which will be added into the alkalinehydrolysis unit when used for the next cadaver.

According to a fourth aspect of the invention, there is provided analkaline hydrolysis unit comprising:

-   -   a chamber for receiving a cadaver to be chemically decomposed by        alkaline hydrolysis;    -   a mixing system adapted to recirculate fluids within the        chamber;    -   wherein the mixing system is operable at temperatures up to 180        degrees centigrade.

Typically, the mixing system comprises a recirculation pump fluidlyconnected to the chamber of the alkaline hydrolysis unit. Typically, therecirculation pump comprises a seal-less stainless steel recirculatingpump. The recirculation pump may be a magnetic drive recirculation pump.

Alternatively, the mixing system comprises a high temperature impellermixing system.

According to a fifth aspect of the invention, there is provided analkaline hydrolysis unit comprising:

-   -   a chamber for receiving a cadaver to be chemically decomposed,        the chamber including a head-receiving part, intended to receive        the head of the cadaver;    -   a recirculation pump fluidly connected to the chamber of the        alkaline hydrolysis unit and adapted to recirculate fluids        within the chamber;    -   a head retaining means locatable in the chamber, for retaining        the head of the cadaver in the head-receiving part of the        chamber; and    -   at least one recirculation jet fluidly connected to the        recirculation pump and positioned to aim fluid from the        recirculation pump at the head-receiving part of the chamber.

Aiming the recirculated fluid at the head of the cadaver helps to ensurethat the head fully decomposes. The skull is very good at protecting thebrain tissue from chemical attack, and there are only a few entry placesfrom which the chemicals can penetrate, e.g. the nose and the eyesockets. Aiming the fluid directly at the head can considerably reducethe time needed to dissolve a cadaver, e.g. from 7-8 hours to 2-3 hours.

The head retaining means prevents the head from floating on the surfaceof the fluids in the chamber, should the head become detached from therest of the cadaver.

The jet may optionally project into the chamber, in close proximity tothe the head-receiving part of the chamber.

Optionally, the alkaline hydrolysis unit includes a support frame, andthe head retaining means comprises part of the support frame.Optionally, the head retaining means comprises a tunnel, adapted to atleast partially surround a head of a cadaver. Optionally, thehead-receiving part of the chamber is bounded by an underside of thetunnel, the recirculation jet and an end of the chamber. Optionally, thetunnel includes an aperture in a wall thereof which, when the supportframe is correctly positioned in the chamber, is aligned with therecirculation jet.

Alternatively, the head retaining means comprises a strap.

Preferably, the head retaining means is adapted to restrain verticalmovement of a head of a cadaver in the chamber. Optionally, the headretaining means is adapted to restrain movement of a head of a cadaverin all directions.

Optionally, the location of the head retaining means is adjustablerelative to the longitudinal axis of the chamber.

Optionally, the alkaline hydrolysis unit is adapted for use with acoffin, insertable within the chamber, and which has a profile shaped toco-operate with the inner profile of the chamber when the coffin isinserted in a correct orientation (e.g. head first), and shaped not toco-operate with the inner profile of the chamber when the coffin isinserted in the opposite, incorrect orientation (e.g. feet first),thereby preventing entry of the coffin into the chamber in the incorrectorientation. Optionally, the recirculation jet may form part of theco-operating inner profile of the chamber.

According to a sixth aspect of the invention, there is provided a systemfor disposing of a cadaver, the system comprising:

-   -   an alkaline hydrolysis unit;    -   an insulated water tank; and    -   a heat exchange means for heating water stored in the insulated        water tank using heat from the alkaline hydrolysis unit.

Typically, the heat exchange means includes a conduit for conveyingwater through a body of fluid in the alkaline hydrolysis unit, or forconveying fluid from the alkaline hydrolysis unit through a body ofwater.

Optionally, the heat exchange takes place in the alkaline hydrolysisunit, e.g. the heat exchange means can comprise a heating/cooling tubelocated within the alkaline hydrolysis unit. In such embodiments, heatedwater from the heating/cooling tube can be conveyed through a conduitinto the insulated tank. The heated water can be stored in the insulatedtank until the alkaline hydrolysis unit has received the next cadaver,at which point the heated water can be conveyed from the insulated tankback into the alkaline hydrolysis unit.

Alternatively, the heat exchange takes place in the insulated tank. Forexample, the insulated tank can comprise a heat exchanger.

In such cases, the heat exchange means typically comprises a steel coilheat exchanger, which includes a chamber and a steel conduit (e.g. acoil) located within the chamber.

In such embodiments, mains water can be provided in the chamber, and hotwaste fluids from the alkaline hydrolysis unit can be conveyed throughthe steel conduit. The hot waste fluids heat the water in the chamber asthey pass through the steel conduit. The heated mains water is stored inthe insulated tank, and when the alkaline hydrolysis unit has receivedthe next cadaver, the heated water can be conveyed from the insulatedtank back into the alkaline hydrolysis unit.

Re-filling the alkaline hydrolysis unit with water from the insulatedtank that is already hot reduces the energy needed in reheating thealkaline hydrolysis unit, and reduces the time required to decompose thenext cadaver.

Typically, the system also includes a steam generator, connected to thealkaline hydrolysis unit and adapted to heat the alkaline hydrolysisunit.

Typically, the system also includes a chemical storage unit, which isoptionally connectable to the alkaline hydrolysis unit.

Optionally, the system also includes a flash tank, into which wastefluids from the alkaline hydrolysis unit are conveyed, prior todisposal.

According to a seventh aspect of the invention, there is provided amethod of disposing of a cadaver, the method including the steps of:

-   -   placing the cadaver in an alkaline hydrolysis unit;    -   adding water and a chemical into the alkaline hydrolysis unit        with the cadaver and heating the inside of the alkaline        hydrolysis unit, to break down the cadaver by an alkaline        hydrolysis process into a fluid component and a bone residue        component;    -   conserving at least some of the heat created; and    -   using this heat to heat the alkaline hydrolysis unit when used        for a subsequent cadaver.

Preferably, the chemical comprises potassium hydroxide. Alternatively,the chemical comprises sodium hydroxide.

Typically, the heat is conserved by transferring a heated fluid to aninsulated heat tank.

Optionally, the heated fluid comprises water that has been used to coolthe alkaline hydrolysis unit. Typically, this heated water is added intothe alkaline hydrolysis unit when used for the next cadaver.

Alternatively, the heated fluid comprises waste fluid from the alkalinehydrolysis process. Typically, this heated waste fluid is used to heatmains water, which will be added into the alkaline hydrolysis unit whenused for the next cadaver.

According to an eighth aspect of the present invention, there isprovided a method of disposing of a cadaver, the method including thesteps of:

-   -   connecting a recirculation pump to a chamber of an alkaline        hydrolysis unit;    -   connecting a recirculation jet to the recirculation pump, and        aiming the recirculation jet at a head-receiving part of the        chamber;    -   placing the cadaver into the chamber so that the head of the        cadaver is located in the head-receiving part of the chamber and        the recirculation jet is aimed at the head;    -   using a head retaining means to retain the head of the cadaver        in the head-receiving part of the chamber;    -   filling the chamber with a mixture of a chemical and water; and    -   activating the recirculation pump to aim recirculated fluid, via        the recirculation jet, at the head of the cadaver, thereby        breaking down the cadaver into a fluid component and a bone        residue component by alkaline hydrolysis.

Optionally, the head retaining means is part of a support frame, andwherein the method includes the step of inserting the head of thecadaver into that part of the support frame.

Alternatively, the head retaining means comprises a strap that isattachable to a support frame, and wherein the method includes the stepof using the strap to fix the head of the cadaver to the support frame.

Optionally, the method includes the steps of:

-   -   heating the inside of the alkaline hydrolysis unit;    -   conserving at least some of the heat created; and    -   using this heat to heat the alkaline hydrolysis unit when used        for a subsequent cadaver.

An embodiment of the invention will now be described, by way of exampleonly, and with reference to the following drawings, in which:

FIG. 1 shows a schematic diagram of an alkaline hydrolysis unit of theinvention;

FIG. 2 shows a perspective view of a metal frame used with a coffinaccording to one embodiment of the invention;

FIG. 3 shows a plan view of the base of the FIG. 2 frame;

FIG. 4 shows a side view of the FIG. 2 frame;

FIG. 5 shows a perspective view of a dissolvable receptacle of thecoffin;

FIG. 6 shows a detail A of FIG. 5 and in particular shows the attachmentof the dissolvable receptacle to the metal frame;

FIG. 7 shows a sectional view of the dissolvable receptacle, taken alongthe line X-X in FIG. 5;

FIG. 8 shows an enlarged view of a post of the FIG. 2 frame, engaged ina receptacle in the base of the frame;

FIG. 9 shows a schematic diagram of a first overall system for disposingof human remains using an alkaline hydrolysis process;

FIG. 10 shows a schematic diagram of a second overall system fordisposing of human remains using an alkaline hydrolysis process;

FIGS. 11 a, 11 b and 11 c show plan, side and end views respectively ofa bone retaining tray;

FIGS. 12 a, 12 b and 12 c show plan, side and end views respectively ofthe bone retaining tray of FIGS. 11 a, 11 b and 11 c, and a coffin ofanother embodiment of the invention loaded on the tray;

FIGS. 13 a and 13 b show sectional views of the alkaline hydrolysis unitof FIG. 1, with the coffin and bone retaining tray of FIGS. 12 a, 12 band 12 c therein;

FIG. 14 shows a side view of the bone retaining tray of FIGS. 11 a, 11 band 11 c and a coffin of a further embodiment of the invention loaded onthe tray; and

FIG. 15 is a schematic drawing and shows the coffin of FIG. 14, with anon-dissolvable mesh receptacle located inside the coffin.

Referring now to FIG. 1, this shows an alkaline hydrolysis unit 10comprising a stainless steel pressure vessel 12. The pressure vessel 12is a 304L/316L vessel and is rated to achieve up to 180 degreescentigrade working temperature. The pressure vessel 12 has a stainlesssteel door 14 with a handle 16. The door 14 can be manually latched orhave an automated (hydraulic) latching alternative. The alkalinehydrolysis unit 10 is clad in 304 stainless steel shroud on all sideswith easy removable panels (not shown).

The pressure vessel 12 is skid mounted, i.e. the pressure vessel 12 haslegs 18 and a skid 20. The legs 18 are provided with lifting brackets22.

The pressure vessel is hollow and defines a chamber 24 within thepressure vessel 12. Inside the chamber 24 is a spray bar 26, which ismounted in an upper part of the chamber 24. The spray bar 26 is elongateand has nozzles 28 distributed along its length. The spray bar 26 has awater inlet 30.

At the bottom of the chamber 24, at the end of the chamber 24 farthestfrom the door 14, is a drain 32 in the form of an aperture in thechamber 24. The drain 32 is attached to an outlet conduit (shownschematically by an arrow). The location of the drain far away from thedoor 14 enables easy rinsing.

Also in the chamber 24 is a hollow heating/cooling tube 34. As will beexplained with reference to FIGS. 9 and 10, the heating/cooling tube 34is attached at both ends to a conduit system. Either hot water, hotsteam, or cold water can be passed through the heating/cooling tube 34,to regulate the temperature of the chamber 24, as required.

Optionally, the chamber 24 includes a stainless steel basket 36, sizedto contain a cadaver. The sides and base of the basket 36 are formedfrom a steel mesh. One end of the basket 36 has a hinged end to allowfolding down. The basket 36 typically has PTFE slide strips on bothsides to enable easy transfer of the basket 36 into the chamber 24.

Optionally, the cadaver can be placed directly in the basket 36. Inalternative embodiments (described with reference to FIGS. 2 to 8), thebasket 36 is not always required, as these Figures show a coffin thatcan be directly located inside the chamber 24, without the need forplacement within a basket 36. In some other embodiments, the hinged endof the basket 36 is folded down, and the coffin of FIGS. 2 to 8 isrolled into the basket 36.

Fluidly connected to the chamber 24 is a seal-less high temperaturestainless steel recirculating pump 38. The pump 38 has an operatingtemperature up to 180 degrees centigrade. The recirculation pump 38 isadapted to recirculate fluids within the chamber 24.

Also in the chamber 24, are one or more jets (not shown) fluidlyconnected to the recirculation pump 38 and positioned to aim fluid fromthe recirculation pump 38 at the part of the chamber 24 of the alkalinehydrolysis unit 10 intended to receive the head of the cadaver. The jetsare positioned so that they aim fluid from different directions.

Optionally, a head retaining means (e.g. a strap) may be provided as acomponent of the chamber 24.

The chamber 24 is provided with integral load cells (not shown), toweigh a cadaver placed in the chamber 24. The pressure vessel 12 alsohas a control system (not shown) comprising a touch screen and boxed instainless steel for wall mounting. The control system includes softwarefor automated weighing of the cadaver and for calculating, based on theweight, the chemical/water mix concentration that will be optimum forthat particular cadaver. The pressure vessel 12 has an integral modem,or other communication means, for remote interrogation.

The chamber 24 also has a chemical inlet 40, by way of which chemicalsfor the alkaline hydrolysis process can be introduced into the chamber24.

Referring now to FIGS. 5 to 7, there is shown a coffin for use in analkaline hydrolysis process. The coffin comprises a dissolvablereceptacle 44 for receiving a cadaver. The dissolvable receptacle 44 maybe a cloth receptacle.

The dissolvable receptacle 44 is supported by a metal support frame 42,which may be of stainless steel (see FIGS. 2 to 4 and 8). The frame 42includes a base 46, which is a rectangular planar member that comprisesa stainless steel mesh. The mesh has holes of around 5 mm in diameter.

The base 46 has a rim 48 on its two longitudinal sides and at one end.The rim 48 has a dimension of approximately 20-40 mm. Eight posts 50 areattachable to the base 46, four of the posts 50 being located along eachlongitudinal side rim 48, at approximately equally spaced intervals. Theposts 50 are removable from the base 46 and engage in welded female pushfittings 52, which are built into the rims 48 (see FIGS. 3 and 8). Thelower ends of the posts 50 are formed with respective corresponding malepush fittings 54, e.g. beveled push fittings. In alternativeembodiments, the female and male push fittings 52, 54 can be replaced bya screw-threaded connection.

The frame 42 includes a head retaining means, which comprises a headstrap 56 which engages in two slots 58. One slot 58 is provided in therim 48 on each opposite longitudinal side of the frame 42. The slots 58extend all the way through the rims 48, in a plane parallel to the planeof the base 42.

The head strap 56 can be moved along the length of the slots 58, to suitcadavers of different heights. In this way, the location of the headretaining means is adjustable along the longitudinal axis of the coffin.

Low friction feet, in the form of six stainless steel castors (wheels)60 are provided on the underneath side of the base 42. These allow theframe 42 to be easily rolled on a surface.

Turning now to FIGS. 5 to 7, the dissolvable receptacle 44 comprises abag 62. The bag 62 is generally box shaped (cuboid), and sized to beslightly smaller than the frame 42, when held under light tension. Thebag 62 has two longitudinal side panels 64, two end panels 66, a basepanel 68 and a top panel 70, each of which are rectangular, to form thecuboid shape. The top panel 70 is formed from two halves, splitlongitudinally, each of the halves being attached to its nearest sidepanel 64. The two halves of the top panel 70 are connectable by a zip72. The zip 72 can be closed to tension the top panel 70, or opened toallow a cadaver inside the bag 62 to be viewed. Other fastening meansmay be used instead of a zip, for example hook and loop fasteners, andthe fasteners may be positioned to the side rather than in the centre ofthe top panel 70.

In this embodiment, the dissolvable receptacle 44 is formed from silk.In alternative embodiments, the dissolvable receptacle 44 may comprise(alternatively or additionally) wool or a dissolvable starch basedbiopolymer. Alternatively, the dissolvable receptacle can be made fromany suitable material which is dissolvable in an alkaline hydrolysisprocess.

The coffin also includes a waterproof liner 74 that is adapted to fitwithin the bag 62, and which is sewn into the inside of the bag 62. Asshown in FIG. 7, the waterproof liner 74 is sewn into the lower part ofthe bag 62, and fits quite snugly in the base of the bag 62.

The waterproof liner 74 prevents body fluids from leaking out of thereceptacle 44.

The waterproof liner 74 can comprise an open bag (to allow viewing ofthe cadaver), or a fully sealable, closed, bag. Embodiments comprising aclosed bag can be used for cadavers which have an infectious disease.

The waterproof liner 74 comprises a starch based biopolymer material.

In alternative embodiments, the dissolvable receptacle 44 is inherentlywaterproof (e.g. if the receptacle 44 is made from a dissolvable starchbased biopolymer), and a separate waterproof liner 74 is not required.

The receptacle 44 can be attached to the frame 42 by means of hooks 76provided on the posts 50 of the frame 42, which engage withcorresponding silk loops 78 provided on the longitudinal side panels 64of the bag 62.

Hence, the hooks 76 and the loops 78 comprise attachment means of thereceptacle 44 and the frame 42.

Each post 50 is provided with three hooks 76, one at the top, the middleand the bottom end of the post 50.

The coffin is provided with an outer casing (not shown), which resemblesa conventional, wooden coffin, for presentation to the public. The outercasing comprises a plurality of wooden panels sized to at leastpartially surround the coffin.

In use, a coffin assembly (the coffin and the frame) is created, withthe posts 50 being located in the female push fittings 52 of the frame42. The dissolvable receptacle 44 (and integral waterproof liner 74) isplaced into the assembled frame 42, and the loops 78 are located overthe hooks 76, so that the dissolvable receptacle 44 is supported by theframe 42. (In embodiments where the waterproof liner 74 is used but isnot integral with the receptacle 44, the waterproof liner 74 can bepositioned in the receptacle 44 and optionally secured thereto.)

The coffin assembly is rigid, so it can be easily handled by thecrematorium operators.

The outer casing is now placed around the coffin assembly (or the coffinassembly is placed inside the outer casing).

The zip 72 is unzipped and a cadaver is placed in the receptacle 44.

Now, the cadaver is ready for presentation at the funeral ceremony (ifrequired), with the zip 72 optionally being left open so that thecadaver can be viewed at the ceremony. The mourners see the outercasing, which resembles a conventional coffin, and the cadaver lyinginside a silk lining of the coffin assembly.

Alternatively, if the zip 72 is closed, the cadaver is fully hidden fromview, and the shape of the cadaver is not shown (in contrast to ashroud).

Alternatively, if the cadaver has a contagious disease, a fully sealedwaterproof liner 74 could be used instead of an open waterproof liner74, in which case the cadaver is also hidden from view.

After the funeral ceremony, the coffin disappears from public view andcan be now prepared for the alkaline hydrolysis process. First, the endsof the outer casing are folded down, and the coffin assembly is removedfrom the outer casing. The outer casing can now flat packed down, andcan be sent back to the funeral directors, optionally with a frame 42from the previous alkaline hydrolysis process.

The head strap 56 is now secured to fix the head of the cadaver to themetal frame 42.

The door 14 of the pressure vessel 12 is opened, and the coffin assemblycan now be rolled, using the castors 60, into the chamber 24 of thealkaline hydrolysis unit 10. As described above, the coffin assembly caneither be located in the basket 36, or the coffin assembly can be usedinstead of the basket 36.

The door 14 is now locked. The integral load cells weigh the cadaver,and the control system calculates, based on the weight, thechemical/water mix concentration that will be optimum for thatparticular cadaver. The aim is to achieve a starting concentration ofaround 1-1.5 Molar (pH 12-14) Hydroxide solution. (Alternatively, theweighing and the calculations may be done manually).

Chemicals and water are then added into the chamber 24 in thatconcentration, via the chemical inlet 40 and the water inlet 30 andspray bar 26, until the chamber 24 is slightly more than half full. Inthis example, the chemical used is potassium hydroxide, butalternatively, sodium hydroxide could be used. Potassium hydroxide ispreferred because it is more eco-friendly.

Steam from a steam generator is now passed through the heating/coolingtube 34. Alternatively, or additionally, steam can be directly injectedinto the chamber 24. The chemical/water mix in the chamber 24 is heatedby the steam to a temperature of 150-180 degrees centigrade, and thepressure in the chamber 24 rises to 3-10 bar gauge.

After the temperature has risen the required amount, this temperature ismaintained for a certain “holding” time, to enable the chemicals to acton the cadaver to decompose the cadaver.

During the heating process and the subsequent “holding” time, therecirculation pump 38 is used to rapidly recirculate the fluids insidethe chamber 24. This ensures a consistently homogeneous solution.

The jets that are fluidly connected to the recirculation pump aim therecirculated fluid at the head of the cadaver. This helps to providegood chemical availability at the brain tissue area, which is importantto ensure that the brain tissue fully decomposes. Optionally, the jetsproject into the chamber 24 and the outlet ports thereof may bepositioned in close proximity to the head of the cadaver. The head strap56 stops the head from floating around the chamber 24, if it breaks offfrom the neck. This ensures delivery of the chemicals forcefully anddirectly to the head.

After the required holding time (which may be 2-3 hours), the cadavershould have been fully decomposed. The alkaline hydrolysis process canbe explained with reference to the natural process of decomposition ofcadavers. In alkaline soil, a shallow burial of a body with oxygenavailable would result in a slow decomposition of tissues via alkalinehydrolysis and expedited by bacteria.

In the alkaline hydrolysis unit 10, the cadaver decomposes in analkaline solution, similar to how it would decompose in nature, but morequickly. Specifically, the cadaver is “resolved” into its constituentelements.

Principally, the cadaver is broken down into calcium phosphate bone andteeth remains (hereinafter referred to as “bone shadows”); and organicmaterial in fluid form.

In the alkaline hydrolysis process, the receptacle 44 and the waterproofliner 74 have been fully decomposed, along with the cadaver and anyclothing.

The metal frame 42 has not decomposed, because the metal chosen for theframe 42 is not dissolvable. Hence, what is now left in the chamber 24is (a) the metal frame 42, (b) bone shadows lying on the base 46 of theframe 42, and (c) a homogeneous waste fluid including the organicmaterial from the cadaver, and any dissolved remains of the receptacle44, the waterproof liner 74 and any clothing worn by the cadaver.

Next, cooling water is now passed through the heating/cooling tube 34,to cool the waste fluid down to a temperature at which it can beaccepted by the local drainage system.

During this process, the “cooling” water used to cool the chamber 34becomes hot. Some of this hot water can be collected, for later use (seebelow).

Once the waste fluid in the chamber 24 reaches the desired lowertemperature, it leaves the chamber 24 via drain 32, and can be dumpedinto the local drainage system, or an effluent tank, as required.Optionally, the waste fluid leaving the chamber 24 is delivered into aflash dump cooling tank. This reduces the amount of time the waste fluidhas to spend in the chamber 24, being cooled, which speeds up the cycletime—i.e. the alkaline hydrolysis unit 10 will be ready quicker for thenext cadaver.

It should be noted that no vacuum is applied to the pressure vessel 12,and any venting of the chamber 24 is via the drain 32.

After the waste fluid has been drained, the bone shadows are removedfrom the chamber 24 via the door 14 (note, there is no rim 48 on the endof the frame 42 nearest the door 14, which facilitates the removal ofthe bone shadows).

The collected hot water (formerly the cooling water) can now be used tohot rinse the bone shadows. Some surfactant detergent can also be added,to wash residual fatty deposits from the bone shadows. The bone shadowsare then dried and crushed, and can be presented to the relatives (as isdone with the ashes, after a cremation).

The frame 42 is now removed from the chamber 24. The posts 50 can beremoved from the base 46 of the frame 42, to enable easy and lighttransportation of the frame 42 back to the funeral directors, togetherwith the flat packed outer casing for the next coffin to be processed.

One embodiment of an overall system used in the alkaline hydrolysisprocess can be seen in FIG. 9. FIG. 9 will now be used to explain inmore detail some aspects of the alkaline hydrolysis process describedabove.

The alkaline hydrolysis unit 10 of FIG. 1 is shown in the centre. To theleft hand side, is shown a store of potassium hydroxide 80, to be addedto the chamber 12 via chemical inlet 40.

At the top, is shown a steam generator 82, which has conduits 82 a, 82 bthat are fluidly connectable to the heating/cooling tube 34. In thisway, in the heating stage, the steam to heat the chamber 12 is generatedby the steam generator 82, flows through conduit 82 a into theheating/cooling tube 34, and is returned to the steam generator viaconduit 82 b.

A mains water supply 84 is also fluidly connectable to theheating/cooling tube 34, via a water conduit 84 a. In the cooling stage,the water conduit 84 a is connected to the heating/cooling tube 34, andmains water flows therethrough. In the heating/cooling tube 34, heat istransferred from the chamber 24 into the water flowing through theheating/cooling tube 34, so that the chamber 24 becomes cooler and thecooling water becomes hot.

The heated mains water leaves the heating/cooling tube 34 via a furtherwater conduit 84 b, which leads into the inlet of an insulated stainlesssteel hot water tank 86. This hot water can now be stored in the tank 86until the next cadaver is ready to be processed in the alkalinehydrolysis unit 10.

When the next cadaver is ready to be processed, hot water is fed fromthe hot water tank 86, via conduit 86 a, into the water inlet 30 and thespray bar 26. Thus, the water that is delivered into the chamber 24 onthe subsequent cycle is already hot. This saves a lot of energy, ascompared to filling the chamber 24 with cold water, and heating thiswater. Furthermore, the feed water already being hot also drasticallyreduces the heating time of the subsequent cycle. Also, as explainedabove, some of the water from the hot water tank 86 can be used to hotrinse the bone shadows.

A centrifugal pump 87 is located in the conduit 86 a, to pump the waterback to the water inlet 30. The pump 87 enables rapid refilling andpowerful rinsing.

At the bottom of FIG. 9 is shown an underground effluent tank 90. At theend of the process, once the waste fluids have been sufficiently cooled,a conduit 90 a takes the waste fluids from the outlet 32 to the effluenttank 90. Optionally, the rinse water can be diverted to a sewer.

The waste fluids could optionally then be taken offsite, in a tanker 92,for conversion to a soil improver.

FIG. 10 shows an alternative embodiment of the overall system of FIG. 9.This system is very similar to that shown in FIG. 9, and like parts aredesignated with like reference numbers.

The steam generator 82 and process of heating the chamber 24 is exactlythe same as in FIG. 9. However, the process of cooling the chamber 24 isdifferent.

In FIG. 10, water from the mains supply 84 is delivered directly into aninsulated stainless steel hot water tank 94 via the conduit 84 a. Thehot water tank 94 comprises a steel coil heat exchanger 96. The heatexchanger 96 includes a main chamber 96 c (into which the mains water isdelivered) and a steel conduit 96 t located within the main chamber 96c. The steel conduit 96 t is formed into a coil.

The drain 32 of the pressure vessel 12 is fluidly connected via conduit98 a to an inlet of the steel conduit 96 t. An optional branch conduit98 b of the conduit 98 a can take rinse water directly to a sewer.

In such systems, the waste fluids do not necessarily have to be cooled(or at least, not cooled to such a great extent) in the pressure vessel12, because they are drained out through conduit 98 a, and into thesteel conduit 96 t. In the conduit 96 t, the hot waste fluids transferheat through the walls of the conduit 96 t to the mains water stored inthe chamber 96 c. In this process, the waste fluids become cooler, andthe mains water is heated.

The outlet of the conduit 96 t is connected via a conduit 100 to a flashtank 102, in which pressure is relieved and the waste fluids are cooledfurther.

The outlet of the flash tank 102 is connected via a conduit 102 a to theunderground effluent tank 90. The waste fluids can then be taken offsite(as described with reference to FIG. 9) or they can be taken (e.g. by atractor 104) to be used onsite as a soil improver. Of course, the wastefluids in FIG. 9 could also be used onsite as a soil improver.

Turning back to the hot water tank 94, when the next cadaver is ready tobe processed in the alkaline hydrolysis unit 10, water from an outlet ofthe chamber 96 c is fed via a conduit 96 a into the water inlet 30 andspray bar 26 of the alkaline hydrolysis unit 10. Therefore, the waterused to fill the chamber 24 is already hot, which greatly reduces theenergy needed to heat the chamber 24, and the heating time required, aswith the FIG. 9 system.

As an example only, the volume of each of the hot water tanks 86, 94 isaround 1,500 liters.

The effluent tank 90 can be plastic (e.g. MDPE) and located undergroundto allow drainage of the waste fluids to the effluent tank 90 undergravity.

Preferred embodiments of the invention enable a cycle time of only 2 to2.5 hours of the cadaver being in the alkaline hydrolysis unit 10.

FIGS. 11 a, 11 b and 11 c show an alternative support frame in the formof a bone retaining tray 110. The bone retaining tray 110 is analternative to the basket 36 shown in FIG. 1.

The bone retaining tray 110 comprises a coffin-receiving flat traymember 112 and a head-retaining means 114, both of which are typicallystainless steel perforated mesh. The tray member 112 has approximatelythe same length and width as a coffin and is substantially flat, exceptthat its two longitudinal edges are inclined upwards at around 30degrees. These upwardly inclined edges form rails 116, which areprovided with Polytetraflouroethylene (PTFE) runners to allow the tray110 to be easily inserted into, and removed from, the alkalinehydrolysis unit 10. The rails 116 may be formed integrally with the restof the flat tray member 112, or may be formed separately and fixedthereto.

The head-retaining means 114 is fixed to (or formed integrally with) thetray member 112 at one end thereof. The head-retaining means 114comprises a tunnel, and has a crown end 118 which receives the crown ofthe cadaver's head, and a neck end 120, which receives the cadaver'sneck. The crown end 118 of the tunnel is optionally closed, whilst theneck end 120 is open to receive the head of the cadaver. Thehead-retaining means 114 flares outwardly towards the neck end 120, suchthat the neck end 120 of the tunnel is wider than the crown end 118.

The head-retaining means 114 is provided with an aperture 122 in itsupper wall. The aperture 122 is very close to the neck end 120.

FIGS. 12 a, 12 b and 12 c show the bone retaining tray 110 with abioplastic coffin 130 according to a further aspect of the inventionloaded thereon.

The bioplastic coffin 130 is an alternative coffin to the silkembodiment of FIGS. 5 to 7.

The bioplastic material is a “Mater-Bi™ thermoplastic biodegradablepolymer”. Specifically, the bioplastic material is known as “Mater-BiTF01U/095R” and is available from Novamont SpA, Via Fauser, 8 I-28100,Novara, Italy. Its composition is a biodegradeable polyester containingmonomers from vegetable oils. The bioplastic coffin 130 is fullydissolvable in the alkaline hydrolysis process. The bioplastic coffin130 includes a head end 132 and a feet end 134.

The bioplastic coffin 130 comprises a substantially rigid container,which surrounds and fully encloses the cadaver. The container isinjection-moulded. The container typically has a base portion and a lid(not shown), for easy insertion of a cadaver. In this embodiment, thebioplastic coffin 130 is shaped like a sarcophagus, but alternativeshapes may also be used. After a fairly flat head portion, the upperprofile of the bioplastic coffin 130 (typically on the lid) risessteeply to a peak 136 in the chest area of the cadaver, which then fallsaway smoothly to the feet end 134.

FIGS. 13 a and 13 b show the bioplastic coffin 130 in place in thealkaline hydrolysis unit 10, supported on the bone retaining tray 110.

The bone retaining tray 110 and supported bioplastic coffin 130 arelocated in the chamber 24, with the head retaining means 114 beingpositioned in a head-receiving part of the chamber 24. In thisembodiment, the head-receiving part of the chamber 24 is the end that isfurthest from the door 14. The “head-receiving part” of the chamber 24means the general area of the chamber 24 which receives the head.

The alkaline hydrolysis unit 10 has already been described withreference to FIG. 1, but some additional details are shown in FIGS. 13 aand 13 b. These include a recirculation jet 138, which is fluidlyconnected to the recirculation pump 38 (shown in FIG. 1) by means of aconduit 139. The recirculation jet 138 enters the chamber 24 from itstop, and extends downwards as far as the top of the head retaining means114. The position of the recirculation jet 138 and the position of theaperture 122 in the head retaining means 114 are selected so that, whenthe bioplastic coffin 130 is correctly positioned in the chamber 24, therecirculation jet 138 is aligned with the aperture 122. The tip of therecirculation jet 138 lies at, or very close to, the aperture 122. Thepurpose of the aperture 122 is to prevent interference of the headretaining means 114 with the recirculation jet 138.

Due to the shape of the upper profile of the bioplastic coffin 130 (inparticular its varying height), and the distance to which therecirculation jet 138 extends into the chamber 24, it is not possible toinsert the bioplastic coffin 130 into the chamber 24 in the wrongorientation (i.e. feet first). If this were attempted, the bioplasticcoffin 130 could not fit into the chamber 24 because the upper profileof the bioplastic coffin 130 would abut against the recirculation jet138. Also, the feet end 134 of the coffin 130 would not fit fully withinthe tunnel of the head retaining means 114.

Hence, the bioplastic coffin 130 has a profile shaped to co-operate withthe inner profile of the chamber 24 when the bioplastic coffin 130 isinserted in one orientation (head first), and shaped not to co-operatewith the inner profile of the chamber 24 when the bioplastic coffin 130is inserted in the opposite orientation (feet first), such that thecoffin 130 can only fit into the chamber 24 when in its correctorientation. In this embodiment, the recirculation jet 138 forms part ofthe co-operating inner profile of the chamber 24.

Also shown in FIG. 13 a is a drain conduit 140, connected to the drain32 and which can also be a recirculation suction conduit; and arecirculation return conduit 142; both of which are connected to thebase of the chamber 24.

Various conduits/other equipment are also connected to the top of thechamber 24. Besides the conduit 139 and the water inlet 30 (used to filland rinse the chamber 24), these include a vacuum breaker 144, a vent146, a pressure relief valve 148, a pressure transducer 150, a pressuregauge and switch 152, and a vessel thermocouple 154.

In use, the embodiment shown in FIGS. 11 to 13 functions in the same wayas explained in respect of FIGS. 1 to 10. Aiming the recirculated fluiddirectly at the head of the cadaver via recirculation jet 138 helps toensure that the head fully decomposes. This can considerably reduce thetime needed to dissolve a cadaver.

The head retaining means 114 retains the head of the cadaver in thehead-receiving part of the chamber 24. As shown in FIG. 13 a, becausethe aperture 122 is very close to the neck end 120 of the head retainingmeans 114, the head of the cadaver (or most of the head) lies to theright of the recirculation jet 138 and the aperture 122. If the head ofthe cadaver were to break off from the neck, the head is restrained fromfloating vertically upwards, and from moving laterally, due to the headretaining means 114 (see FIG. 13 b). Floatation is the most likely typeof movement to occur. However additionally, the head cannot movelongitudinally to the left in FIG. 13 a (towards the feet end of thechamber) due to the recirculated fluids from the jet 138 impacting inwhat was the neck area of the cadaver, thereby urging the head of thecadaver to the right. The head cannot move to the right due to abutmentagainst either the crown end 118 of the tunnel (if closed) or the wallof the chamber 24.

An alternative embodiment of a bioplastic coffin 160 is shown in FIG.14, located on the tray 110. The bioplastic coffin 160 comprises aflexible bag, instead of a substantially rigid container. The flexiblebag has a thickness of approximately 100 microns.

The material of the bioplastic coffin 160 is a “Mater-Bi™ thermoplasticbiodegradable polymer”. Specifically, the composition comprises starch,polyesters and plasticizers. This bioplastic material is available fromNovamont SpA, Via Fauser, 8 I-28100, Novara, Italy.

The bioplastic coffin 160 is fully dissolvable in the alkalinehydrolysis process. The bioplastic coffin 160 includes a head end 162and a feet end 164.

The tray 110 and flexible bioplastic coffin 160 is inserted into thealkaline hydrolysis unit 10, in the same way as shown in FIG. 13 inrespect of the non-flexible bioplastic coffin 130. In use, theembodiment shown in FIG. 14 functions in the same way as explained inrespect of FIGS. 11 to 13.

FIG. 15 shows the flexible bioplastic coffin 160 of FIG. 14, and also anon-dissolvable plastic mesh receptacle 170 inside the bioplastic coffin160. In this example, the mesh is polytetrafluoroethylene (PTFE), butany other non-dissolvable material could alternatively be used. Thecadaver would be placed within the mesh receptacle 170, which in turn iswithin the bioplastic coffin 160. FIG. 15 is a schematic drawing, and inparticular the mesh would be much finer than shown, fine enough toretain substantially all of the bone residue of the cadaver, after therest of the cadaver has dissolved, whilst still being course enough toallow the flow of fluids into and out of the mesh receptacle 170.

Modifications and improvements can be incorporated without departingfrom the scope of the invention. For example, the dissolvable receptaclecan be made from any material that is decomposable in an alkalinehydrolysis process.

The coffin assembly does not necessarily need to be a cuboid shape, andcould be any shape, although it is preferable if the coffin conceals theshape of the cadaver when closed.

The coffin is not necessarily closable—e.g. the dissolvable receptaclecould be open at its upper surface.

The frame 42 could optionally have a different form, e.g. more or fewerposts, and the base of the frame is not necessarily a mesh.

In some embodiments, the hot water tanks of FIGS. 9 and 10 are not used,and water from the mains water supply is heated from cold in thealkaline hydrolysis unit 10.

The means to heat and cool the chamber 12 is not necessarily viaheating/cooling tube 34. Any suitable heating/cooling means can be used.For example, direct gas injection, or any kind of conduction/convection.

In some embodiments, all waste fluids go directly into the sewer systemafter cooling (not via any effluent tank/flash tank).

In some alternative embodiments, all waste fluids to into the sewersystem, via a flash tank, and then into the sewer system (but not viaany effluent tank).

In accordance with the fourth to the eighth aspects of the presentinvention, it should be noted that the presence of a coffin of the firstand second aspects of the invention is not an essential feature in suchsystems/apparatus/methods.

For example, in some embodiments, a coffin comprising a dissolvablereceptacle is not used, and a cadaver can be placed directly into thebasket 36. Hence, in the above described exemplary method, the stepsrelating to the coffin can be omitted, whilst however retaining any orall of the other method/system/apparatus features.

Any of the features of the eight aspects of the invention can beincorporated and used with any of the other of the eight aspects of theinvention.

In the embodiment of FIGS. 11 a, 11 b and 11 c, the aperture 122 is notnecessarily in the top surface of the head retaining means 114, and therecirculation jet does not necessarily extend downwards from the top ofthe alkaline hydrolysis unit 10. In other embodiments, the aperture 122may be provided in one of the sides of the tunnel, and the recirculationjet could extend into the chamber of the alkaline hydrolysis unit fromone side, instead of from above.

The mesh receptacle 170 of FIG. 15 is shown inside the bioplastic coffin160, but could alternatively be located on the outside, around thebioplastic coffin 160. Since the bioplastic coffin 160 will ultimatelybe dissolved in the process, there is no real difference, as the endresult will still be the bone residue retained within the meshreceptacle 170. Further alternatively, the mesh receptacle 170 may befixed to, or formed integrally with, the bioplastic coffin 160.

Although the mesh receptacle 170 is only illustrated with the flexiblebioplastic coffin 160, it could also be used within or outside of any ofthe other dissolvable receptacles, e.g. the substantially rigidbioplastic coffin 130, or the silk and metal frame embodiment.

The tunnel-shaped head retaining means 114 of FIG. 11 couldalternatively be replaced by a head strap.

1. An alkaline hydrolysis unit comprising: a chamber for receiving acadaver to be chemically decomposed, the chamber including ahead-receiving part, intended to receive the head of the cadaver; arecirculation pump fluidly connected to the chamber of the alkalinehydrolysis unit and adapted to recirculate fluids within the chamber; ahead retaining means locatable in the chamber, for retaining the head ofthe cadaver in the head-receiving part of the chamber; and at least onerecirculation jet fluidly connected to the recirculation pump andposition to aim fluid from the recirculation pump at the head-receivingpart of the chamber.
 2. An alkaline hydrolysis unit as claimed in claim1, wherein the jet projects into the chamber, in close proximity to thehead-receiving part of the chamber.
 3. An alkaline hydrolysis unit asclaimed in claim 1, including a support frame, and wherein the headretaining means comprises part of the support frame.
 4. An alkalinehydrolysis unit as claimed in claim 3, wherein the head retaining meanscomprises a tunnel, adapted to at least partially surround a head of acadaver.
 5. An alkaline hydrolysis unit as claimed in claim 4, whereinthe head-receiving part of the chamber is bounded by an underside of thetunnel, the recirculation jet and an end of the chamber.
 6. An alkalinehydrolysis unit as claimed in claim 4, wherein the tunnel includes anaperture in a wall thereof which, when the support frame is correctlypositioned in the chamber, is aligned with the recirculation jet.
 7. Analkaline hydrolysis unit as claimed in claim 1, wherein the headretaining means comprises a strap.
 8. An alkaline hydrolysis unit asclaimed in claim 1, wherein the head retaining means is adapted torestrain vertical movement of a head of a cadaver in the chamber.
 9. Analkaline hydrolysis unit as claimed in claim 8, wherein the headretaining means is adapted to restrain movement of a head of a cadaverin all directions.
 10. An alkaline hydrolysis unit as claimed in claim1, wherein the location of the head retaining means is adjustablerelative to the longitudinal axis of the chamber.
 11. An alkalinehydrolysis unit as claimed in claim 1, wherein the alkaline hydrolysisunit is adapted for use with a coffin, insertable within the chamber,and wherein the coffin has a profile shaped to co-operate with the innerprofile of the chamber when the coffin is inserted in a correctorientation, and shaped not to co-operate with the inner profile of thechamber when the coffin is inserted in the opposite, incorrectorientation, thereby preventing entry of the coffin into the chamber inthe incorrect orientation.
 12. An alkaline hydrolysis unit as claimed inclaim 11, wherein the recirculation jet forms part of the co-operatinginner profile of the chamber.